Article 100 of the National Electrical Code (NEC) 2023 edition is an important part of the NEC that outlines the definitions used throughout the codebook. It provides a standardized language and vocabulary to be used when discussing the electrical installations, equipment, and materials covered in the NEC. The definitions in Article 100 are important to ensure that everyone who reads the codebook has a clear understanding of the terms used and their intended meanings.
In this article, we will explore the key definitions in Article 100 of NEC 2023 and provide some insight into their significance and how they relate to electrical installations.
General Definitions:
The NEC 2023 defines the term “approved” as being “acceptable to the authority having jurisdiction.” In other words, it refers to an installation, material, or equipment that has been inspected and meets the standards set by the local regulatory body.
“Branch circuit” is another important term defined in Article 100. It refers to a circuit that originates at the final overcurrent device (such as a circuit breaker or fuse) and supplies power to outlets, lights, and other electrical devices in a building. Branch circuits must be sized appropriately to ensure that they can safely carry the load placed on them.
Another term that appears in Article 100 is “equipment grounding conductor.” This refers to a conductor that is used to connect non-current-carrying metal parts of electrical equipment to the grounding electrode system. The equipment grounding conductor is an important safety feature that helps prevent electric shock and fires by providing a low-impedance path for current to flow to the earth.
Wiring Methods:
Article 100 of the NEC 2020 provides definitions for different types of wiring methods, including “conduit,” “cable,” and “raceway.” Conduit is a tube or pipe that is used to protect electrical wires and cables from damage and to provide a pathway for them to run through. Cable refers to a group of insulated wires or conductors that are bound together in a sheath. A raceway is a channel or enclosure that is used to contain and protect wiring.
The NEC also defines different types of conduit, including “rigid metal conduit,” “electrical metallic tubing,” and “liquidtight flexible metal conduit.” Each type of conduit has its own properties and applications, and it is important to choose the appropriate type for the installation to ensure safety and compliance with the code.
Grounding and Bonding:
Article 100 of NEC 2023 provides definitions for terms related to grounding and bonding, including “grounded conductor,” “grounding conductor,” and “bonding jumper.” The grounded conductor is typically the neutral wire in a circuit and is connected to the earth at the service entrance. The grounding conductor is a separate wire that is used to connect metal parts of electrical equipment to the earth. Bonding jumpers are used to connect metal parts that are not part of the electrical circuit, such as metal water pipes and gas lines, to the grounding system.
The grounding and bonding requirements in the NEC are critical to ensure that electrical equipment and installations are safe and do not present a hazard to people or property. Proper grounding and bonding can help prevent electrical shocks and fires, and it is important to follow the requirements set forth in the NEC when designing and installing electrical systems.
Special Occupancies:
Article 100 of the NEC 2023 includes definitions for special occupancies, such as hazardous locations, health care facilities, and swimming pools. These definitions help ensure that electrical installations in these environments are designed and installed to minimize the risk of electrical hazards and fires.
For example, a hazardous location is defined as an area where there is a potential for explosion or fire due to the presence of flammable gases, vapors, or dust. Electrical installations in hazardous locations must be designed and installed to prevent ignition of these flammable materials and to contain any explosions that may occur.
Health care facilities, such as hospitals and clinics, have unique electrical requirements due to the critical nature of the equipment and systems used in these facilities. The NEC defines different types of health care facilities, such as “critical care areas” and “patient care areas,” and provides requirements for electrical systems in these areas to ensure the safety of patients and staff.
Swimming pools are another special occupancy that is covered in Article 100. The NEC defines a swimming pool as “any structure intended for swimming or recreational bathing that contains water over 18 inches deep.” Electrical installations in and around swimming pools must be designed and installed to minimize the risk of electric shock and to comply with specific requirements, such as the use of ground fault circuit interrupters (GFCIs).
Equipment:
Article 100 of the NEC 2023 includes definitions for different types of electrical equipment, such as “disconnecting means,” “overcurrent protective device,” and “ground fault circuit interrupter.” These definitions help ensure that electrical equipment is installed and used safely and in compliance with the NEC.
A disconnecting means is a device or group of devices that is used to disconnect the power to all or part of an electrical installation. An overcurrent protective device is a device, such as a circuit breaker or fuse, that is designed to protect an electrical circuit from overloading and overheating. A ground fault circuit interrupter is a device that detects and interrupts electrical current when it senses a difference in current between the hot and neutral conductors.
Other definitions related to equipment in Article 100 include “listed,” “labeled,” and “identified.” Listed means that a product has been tested and certified by an independent testing laboratory to meet specific safety standards. Labeled means that a product has a label or other marking that indicates its intended use, voltage rating, and other important information. Identified means that a conductor or cable has markings or other means of identification that indicate its voltage rating, insulation type, and other characteristics.
Conclusion:
Article 100 of the NEC 2023 is an important section of the codebook that provides standardized definitions for the terms used throughout the NEC. These definitions help ensure that everyone who reads the codebook has a clear understanding of the terms used and their intended meanings. The definitions in Article 100 are critical to ensuring that electrical installations, equipment, and materials are installed and used safely and in compliance with the NEC.
It is important to remember that the NEC is a minimum safety standard, and that local jurisdictions may have additional requirements or amendments to the code. Electrical contractors and engineers must be familiar with the requirements of the NEC as well as any local codes and regulations that apply to the installation they are working on. By following the requirements set forth in the NEC and other applicable codes and regulations, we can help ensure the safety of people and property from electrical hazards and fires.